PU reweight for 2016

[sungbinoh]

A new function
double MCCorrection::GetPileUpWeight(int syst, int N_vtx)
is added for 2016 pileup reweight based on the official recommendation.
(min-biax X-sec = 69.2 mb, and 66.017 / 72.388 mb for down/up systematics)

If 2017 MC samples without PU profile bug are arrived, we just need to make a new histmap and rootfile to use same function for both campaigns.

For now, the new function "double MCCorrection::GetPileUpWeight(int syst, int N_vtx)"
is only available for 2016 campaign.

So in analysis code, call PU reweight like this

double pileup_reweight = 1.;
if(DataYear == 2016){
pileup_reweight = mcCorr. GetPileUpWeight(0, nPileUp);
}
else(DataYear == 2017){
pileup_reweight = mcCorr.GetPileUpWeightAsSampleName(0, nPileUp);
}
else{
cout << "Whatever" << endl;
}

[sungbinoh]

Also, TTLJ_powheg and TTJJ_powheg PU reweights for 2017 are added